Machines for peeling and cleaning vegetables, fruit and other foodstuffs are already known, but they have not yet given satisfaction when the problem is to peel and clean onions and garlics.
Indeed, the machines existing on the market for peeling vegetables and which have also to peel onions are generally designed according to the principle of a plate rotating in a fixed and substantially cylindrical chamber, the work being obtained by a stirring action of the products in the chamber which brings about, successively in contact with active surfaces, that is surfaces with a more or less rough finish, each element of the charge formed by the vegetables in order to clean them. A discharge permits eliminating the skins and scraps as they are produced, either through the combined effort of the rotation of the plate and the rotation speed of the vegetables, or through the same effort plus a distribution of water which is done under a variable head.
These machines can be classified under three groups which are the following:
(1) The first group comprises machines having a plate and a cylinder coated with abrasives, with a discharge on the side or underneath. These machines generally give excellent results when cleaning tubers, but they are hardly suitable for onions since, in fact, they hurt the flesh rather deeply and consume a large portion of the product. Moreover, evacuation of the skins is difficult since the skins adhere to the wall of the cylinder, which requires cleaning, and, by way of consequence causes hygiene problems. Finally, this arrangement prevents the problem of replacement of the active portion of the cylinder in after-sale service.
(2) The second group consists in using a smooth plate and in having thus a cylinder coated with abrasive provided with a side discharge. These machines are hardly suitable for peeling tubers due to their low efficiency, and they are therefore generally used for peeling only a product such as onions. The results obtained reveal a poor renewal of the charge, and therefore an irregular work, a poor evacuation of the skins which stick to the cylinder, thereby proportionally reducing the efficiency. Finally the side discharge presents also the problem of an added recovery device which increases substantially the overall size of the machine and, moreover, is liable to breakdowns; hence a poor work with a machine of relatively high cost price.
(3) The third group is composed of a hybrid system with a plate coated with an abrasive or cutting blades and a smooth cylinder comprising a deflection ramp, the evacuation being carried out sideways. These machines improve the quality of the work but they still have the disadvantage of a considerable overall size, and moreover it is absolutely necessary to provide an extra recovery system which is outside the volume of the machine. Therefore, such machines have to be considered as not currently usable since their maintenance is difficult, and their cost price high.